1. Field of the Invention
The present invention relates to a manipulation mechanism and a mechanical instrument which is used while being inserted into a body cavity in combination with a soft endoscope.
Priority is claimed on U.S. Provisional Application No. 61/093,492, filed Sep. 2, 2008, the content of which is incorporated herein by reference.
2. Background Art
As a method of performing a medical action such as an observation or a treatment on the internal organs of a human body, there is known a laparoscopic surgery which performs a surgical technique by forming a plurality of openings in an abdominal wall instead of making a large incision, and inserting the medical instruments such as an abdominoscope or a clamp into the respective openings. In such a surgery, since only small openings are formed in the abdominal wall, it is advantageous in that the stress on the patient is reduced.
In addition, as a method of reducing the stress to the patient, a method has been proposed for performing a surgical technique by inserting a soft endoscope through a natural passageway such as patient's mouth, nose, or anus. An example of an endoscope device (medical instrument) used in such a surgical technique is disclosed in US Patent Application Laid-open No. 2005/0065397.
In the disclosed endoscope device, arm portions of which front ends can be bent are respectively inserted through a plurality of lumens disposed in a soft inserting portion inserted through a patient's mouth. When treatment tools are respectively inserted through the arm portions, it is possible to approach the treatment tools to a treatment portion in different directions, and to continuously perform a plurality of surgical techniques in a state in which one endoscope is inserted into a body cavity.
Also, in the arm portion (manipulation mechanism) disclosed in the above-described specification, four pulling wires are disposed along the arm portion so as to be located at the same interval in the circumferential direction. In the pulling wires, the base ends are attached to a steering opening (oscillating body) in the base end of the arm portion, and the front ends are attached to the front end of the arm portion. In addition, it is possible to change a direction of the treatment portion protruding from the front end of the arm portion by curving the front end of the arm portion in such a manner that the base end of the treatment tool communicating with the opening and the arm portion is inclined so as to rotate the opening relative to the arm portion.
However, the method of attaching the opening to the base end of the arm portion is not clearly shown. Additionally, the position of the opening deviates from the base end of the arm portion when the opening is rotated, which may deteriorate the operability of the treatment tool.